Detachable sharpener for a cross-flow mower

ABSTRACT

The sharpener comprises a treadle having a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of the reel of the mower. The treadle is hingeably attached to the mower intermediate the front and rear ends of the treadle with the front section extending beneath the mower reel and the rear section accessible for foot operation. By starting the mower engine and exerting pressure on the rear section of the treadle, the front section sharpens the reel. Advantageously a unitary sheet of stiffly flexible material is employed so that by moving the foot along the rear section different sections of the reel are sharpened.

United Ferguson States Patent 51 May 2,1972

[72] Inventor:

Hugo S. Ferguson, Averill Park, NY.

[73] Assignee: Reel Vortex, Inc., Poestenkill, NY.

2,621,455 12/1952 Stevens.... ..51/250 643,290 2/1900 Herbert l/250 808,434 12/1905 Chesbro ..51/250 Primary Examiner-William R. Armstrong Att0rneyPennie, Edmonds, Morton, Taylor & Adams [5 7] ABSTRACT The sharpener comprises a treadle having a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of the reel of the mower. The treadle is hingeably attached to the mower intermediate the front and rear ends of the treadle with the front section extending beneath the mower reel and the rear section accessible for foot operation. By starting the mower engine and exerting pressure on the rear section of the treadle, the front section sharpens the reel. Advantageously a unitary sheet of stiffly flexible material is employed so that by moving the foot along the rear section different sections of the reel are sharpened.

6 Claims, 9 Drawing Figures PATENTEDMAY 2 I972 SHEET lUF 4 INVENTCR Hugo S. Ferguson av ATTORNEY S PATENTEDMM 2 I972 SHEET 2 BF 4 a. u L t FIG INVENTOR L w e 3 O L J i.

ATTORNEYS PATENTEDMAY 2 1912 SHEET 3 OF 4 FIG. 4

PATENTEDMM 21972 3,659,385

sum w a INVENTOR Hugo S.Ferguson Y Q14 86.... v

ATTORNEY S BACKGROUND OF THE INVENTION In application, Ser. No. 783,192 filed Dec. l2, 1968 by Hugo S. "Ferguson for Cross-Flow Mowing Machine, a mower is described utilizing the action of a cross-flow blower with sharp reel blades to mow grass, etc. without the aidof a fixed blade in shearingrelationship with the reel blades.

Briefly, a cylindrical reel is mounted on a carriage for rotation about a horizontal axis extending laterally of the carriage. The reel has a plurality of circumferentially spaced blades with sharp outer'leading edges. A motor rotates the reel, advantageously with the lower blades moving in the forward direction of travel of the mower. A blower conduit cooperates with the reel to form a blower of the cross-flow type with air flowing through the reel from inlet to outlet regions thereof. At least a portion of the inlet "region opens in the forward direction of travel and the bottom and lower front portion of the reel are uncovered and exposed to grass,e'tc. to be mowed. Vortex action at the leading blades of the reel bend the grass toward the cutting edges of the blades to yield effective mowing without the aid of a fixed blade or bed knife, and the cut grass is discharged from the rear of the blower conduit. Th'e aforesaid application describes several embodiments andgives additional information concerning the design and operation of the mower.

For best operation, it is desirable to keep the reel blades reasonably sharp. Frequent sharpening is not ordinarily necessary, since the entire length of each blade is used and hence the cutting action is evenly distributed. However, occasional sharpening will promote satisfactory cutting and a good lawn appearance. Also, if rocks or other hard objects are struck, local portions of one or more of the reel blades may be dulled.

The present invention is designed to provide a simple detachable sharpener which can be used by a homeowner to sharpen the blades when required. The attachment is suitable for sharpening the entire width of the reel, and in addition may be designed to allow localized sharpening at various points along the reel.

BRIEF SUMMARY OF THE INVENTION In accordance with the invention, a treadle is provided having a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend'across the width of the reel. Attachment means are provided for hingeably attaching the treadle to the mower intermediate the front and rear ends of the treadle with the front section extending beneath the reel and the rear section accessible for foot operation. Pressure on the rear section brings the front section into sharpening engagement with the reel. By starting the engine to rotate the reel, and applying pressure to the treadle, the reel blades are sharpened.

Various means may be providedfor hingeably attaching the treadle to the mower, and will depend in part on the detailed construction of the mower. In the embodiments hereinafter described, both pivoting and flexing type hinges are shown. With the front section of stiffly flexible material, it can be brought into proper sharpening engagement with the reel without requiring careful alignment of the hinge axis with the reel axis.

Advantageously the rear section of the sharpener has a width approximately equal to the width ofthe reel and is stiffly flexible so that pressure on different laterally spaced regions of the rear section produces laterally different engagement forces on the front section. This permits applying greater sharpening forces to one portion of the reel than another so as to remove nicks and sharpen locally dulled sections. Preferably the front and rear sections are' formed of a unitary sheet of stiffly flexible material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cross-flow mower with which the sharpener of the invention may be used;

2. FIG. 2 is a plan view of the mower of FIG. omitted;

FIG. 3 is a side view ofthe mower of FIG. 1 with one form of sharpener shown in place;

FIG. '4 is a cross-section through the reel and blowerhousing of the mower, 'with another form of sharpener shown in l with portions place;

FIG. 5 is aplan view of the sharpener used in FIG. 3;

FIG. 6 shows a-modification of the lower wall of the housing of FIG. 4, with a different form of sharpening attachment;

FIG. 7 is another embodim'ent of cross-flow mower having a .hinged guard plate; and

FIG. 8 shows a form of sharpener adapted for attachment to the guardplate of FIG. 7, and FIG. 8a shows a detail along the liheSa-Sa of FIG. 8.

DESCRIPTION or THE SPECIFIC EMBODIMENTS Referring to FIGS. 1-4, a cross-flow mower is shown like that of FIGS. 10-15 of'application, Ser. No. 783,192, supra. The mower carriage includes side plates 10,11 and wheels 12, 13 mounted thereon. A handle 14 is attached in desired manner. Height adjustment is provided by mounting the wheels on a framework including brackets 15 and 16 which allow rotational adjustment about pivot point 17. A metal bar 18 has several tapped h'oles for receivin'g bolt 19 which passes through a slot in bracket 16. The mounting arrangement is fully described in the aforesaid application and further detail is unnecessary here since it formsno part of the present inventron.

In normal use a roller 21 is mounted between side plates 10 and 11 adjustable to various angular positions about pivot point 22. This is shown in phantom in FIG. 3 since it is removed when the sharpener is attached.

A reel 24 having a plurality of circumferentially spaced blades 25 attached to end disks, one of which is shown at 26 in FIG. 4, is mounted for rotation on axle 27. A pulley 28 is attached to the axle and is driven by motor 29 through a V-belt 31. The blades 25 may be of various types as described in the aforesaid application, and are here shown as formed of flat strip stock with the edge bent over to form a hook (in crosssection) with the outer leading edge 25 sharpened. The straight portion 25 (in cross-section) is tilted backward from inner to outer points thereof with respect to the direction of rotation of the reel. The blades are helically curved from end to end. With the three blades here shown, each blade is twisted through appioximately and welded to the end disks.

The blower conduit and reel are designed to provide crossflow blower action as the reel rotates. To this end, a curved upper plate 32 is attached to the flat plate 33 forming part of the housing and'extends downwardly and forwardly, with an angle piece 34 attached to the front end for rigidity. Curved plate 32 is welded at each end to side plates 10 and 11. A lower plate 35 is bent downward and forward at 36 and is provided with an outturned flange 37. The spacing of the plates from the reel, and the general exponential curvature of upper plate 32, together with the reel, forms a cross-flow blower with air flowing from the inlet region generally indicated as 38 to the outlet region 39, with air flowing through the reel in passing from inlet to outlet regions. The general flow of air in the outlet region is indicated by arrow 41. A chute 42 is attached to the rear of the blower conduit and diverts the discharged air and cut grass to the side of the machine. The chute is detachably mounted on upper plate 33 of the housing.

Turning now to the detachable sharpener of the invention, FIG. 5 shows a plan view of one embodiment and FIG. 3 shows a side view thereof as attached to a cross-flow mower. The sharpener is formed of a flat sheet 51 of stiffly flexible mate rial having an abrasive surface 52 on its upper side which extends across the width of the reel when in sharpening position. Since the abrasive surface will wear, provision is made for replacement. Strips of metal 53, 54 are spot welded to sheet 51 with their inner edges spaced from the sheet to form lips which receive a sheet of abrasive cloth and hold it in place. The abrasive sheet may be slipped out and replaced as necessary.

An L-shaped strip of metal 55 with a turned over lip is attached to sheet 51 intermediate the front and rear ends thereof, as by spot welding, and a pair of spring pressed pivot pins 56, 56' are mounted at the ends thereof. To attach the sharpener to the mower, the'roller 21 is removed, the sharpener slipped under the mower, and the pivot pins inserted in the holes used to mount the roller. Thus the sharpener is a treadle with the rear section accessible for foot operation. To facilitate sharpening, the chute 42 may be removed.

When the sharpener has been attached, the motor 29 is started and the lower blades of the reel move in the forward direction as indicated by arrow 57. Initially the front end of the sharpener will be out of contact with the reel blades due to the weightof the front end, although this is not essential. The operator then presses down on the rear section with his foot, as indicated by arrows 58. This brings the abrasive surface 52 into contact with the reel blades, as shown in FIG. 3, and the blades are sharpened. Inasmuch as the blades are moving forward, away from the pivoting axis of the sharpener, there is no danger to the operator.

With plate 51 of stiffly flexible material, if the pivoting axis of the sharpener is not exactly parallel to the reel axis, the front section will flex to bring the abrasive surface into contact with the blades across the entire width of the reel. Further, due to the flexibility, the portion of the abrasive surface directly in front of the foot will be pressed against the blades with greater force than in other lateral regions. To sharpen the entire width of the reel, the operator moves his foot laterally along the rear section of plate 51, exerting approximately the same pressure for approximately equal lengths of time at each position. If one section of the reel requires more sharpening, the operator presses on the corresponding portion of the rear section for a longer time and/or with greater pressure. When the sharpening has been completed, the sharpener is removed and the roller and chute put back in place.

Plate 51 is sufficiently stiff to withstand the applied forces without excessive bending, while at the same time being sufficiently flexible to bend somewhat under the applied forces, particularly under heavy foot pressures. The degree of stiffness (or flexibility) may be selected as meets the judgment of the designer. In one specific embodiment a 1/16 inch thick sheet of a fairly hard tempered aluminum known as 606IT6 was employed with success. 7

Referring to FIG. 4, a different hinge mounting arrangement is employed. An angle strip 61 of stiffly flexible material such as hard tempered aluminum is spot welded to sheet 51 and extends thereacross. A pair of studs 62 are welded to the out-turned flange 37 of the blower conduit, one near each end of the flange, and strip 61 is provided with matching holes. If desired, additional studs spaced along flange 37 may be used. Slotted spring clips 63 hold the sharpener in place. Normally the front section of the sharpener is slightly away from the reel, but application of pressure as indicated by arrow 64 brings the abrasive surface 52 into sharpening engagement with the reel blades. Angle strip 61 forms a flexing hinge. Or, if desired, spring clips 63 may be relied upon to flex the required amount. Here a sheet of abrasive cloth is cemented to the front section of the sharpener, but the removable mounting of FIGS. 3 and 5 may be employed if desired. The rear section is extended a sufficient distance to provide convenient accessibility for pressure application.

FIG. 6 shows another hingeing arrangement. Here the outturned flange 37 has a further up-turned flange 65. An upstanding strip 66 is welded to plate 51 and has a downwardly extending section 67 on its front side adapted to fit over the top of flange 65. A loose fit may be employed, and reliance placed on foot pressure indicated by arrow 68 and the bearing of abrasive sheet 52 against the reel blades to provide hingeing action in use. If desired, section 67 may be crimped toward upstanding section 66 so as to clip onto the upper portion of flange 66.

FIG. 7 shows a cross-flow mower like that of FIG. 18 of the above-identified application. This mower rolls on a pair of wheels 71, 71 without additional rear wheels or roller. A guard plate 72 is pivotally mounted at 73, 73 on the mower side plates so that, in use, the lower edge of the guard plate slides along the ground and prevents the accidental advance of a foot of the operator into contact with the rotating reel within the housing. Extensions 74, 74 on the sides of the guard plate, and edges 75, 75' of the mower side plates, limit movement of the guard plate when the mower is tilted backward to its rest position.

Guard plate 72 may be removed and the mounting holes for pivots 73, 73 used for attaching the sharpener, similar to that described in connection with FIG. 3. However, since the guard plate is already hinged to the mower, and is in a suitable location, the sharpener may be designed to be attached to the guard plate.

Referring to FIGS. 8 and 8a, the sheet 51 is provided at the rear with a turned over section 81 designed to slip over up turned rear edge 72 of the guard plate. A pair of spring clips are attached to sheet 51 on each side thereof, adapted to clip over the up-turned lateral edges 72" of the guard plate. One of the spring clips is shown in cross-section at 82 in FIG. 8a. The sheet 51 may be bent so that, when the mower is tilted backward and sides 74,74 of the guard plate engage edges 75, 75 of the mower side plates, the front section of the sharpener is out of engagement with the reel. The mower engine may be started in this position. Then, by raising the mower handle and applying pressure to the guard plate, as indicated by arrow 83, the reel blades may be sharpened.

It will be appreciated that the detailed design of the sharpener will depend to some extent on the design of the particular mower or series of mowers with which it is intended to be used. If permanent parts of the mower interfere with the simple configurations illustrated in the specific embodiments, portions of the plate 51 may be cut away, or the plate may be formed with bent sections so as to pass over or under the interfering structure. Also, instead of using a unitary plate with the rear section extending approximatelyv the width of the reel, a narrower more rigid section could be used. This might entail sacrificing the ability to sharpen localized regions of the reel which have been damaged, but would still permit sharpening the reel as a whole.

In use, it is particularly contemplated that foot pressure will be employed, which is very convenient. However, if the user desires, hand pressure could be applied on the rear of the treadle, either directly or with the aid of a stout piece of lumber, etc. With the rear of the treadle accessible for foot operation, it will of course be accessible for such hand operation.

I claim:

1. A detachable sharpener for a cross-flow mower having a carriage and a cylindrical reel mounted thereon for rotation about a horizontal axis extending laterally of the carriage, said reel having a plurality of circumferentially spaced blades with sharp outer leading edges, motor driving means for rotating said reel with the lower blades moving in the forward direction of travel of the mower, and a blower conduit cooperating with said reel to form a blower of the cross-flow type with air flowing through the reelfrom inlet to outlet regions thereof, said blower conduit including upper and lower wall sections and side wall sections extending rearwardly of said reel, at least a portion of said inlet region opening in said forward direction of travel with the bottom and lower front portion of the reel uncovered and exposed to material to be mowed, the crossflow blower action and the blades of the reel mowing material without the aid of a fixed blade in shearing relationship with the reel blades, said detachable sharpener comprising a treadle having a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of said reel, and attachment means for hingeably attaching said treadle to said mower rearwardly of the mower reel and intermediate the front and rear ends of the treadle with said from section extending beneath the mower reel with respect to the normal upright position of the mower and the rear section accessible for foot'operation, whereby pressure on said rear section will bring said front section into sharpening engagement with the reel and the blades thereof sharpened with the mower in its normal upright position and the reel driven by said motor driving means.

2. A detachable sharpener in accordance with claim 1 in which the rear section has a width approximately equal'to the width of said reel and is stiffly flexible, whereby pressure on different laterally spaced regions of the rear section produces laterally different engagement forces on said front section.

3. A detachable sharpener in accordance with claim 2 in which said front and rear sections are sections of a unitary sheet of stiffly flexible material.

4. A detachable sharpener in accordance with claim 3 in which the mower has a flange behind the lower portion of the reel, said attachment means including an upturned strip of stiffly flexible material fixedly attached to said unitary sheet, and means for removably attaching said upturned strip to said flange.

5. A detachable sharpener in accordance with claim 3 in which the mower has an upturned flange behind the lower portion of the reel, said attachment means including an upstanding strip fixedly attached to said unitary sheet, and a downwardly extending section on the front side of said upstanding strip above said unitary sheet, said downwardly extending section and the adjacent portion of the upstanding strip being adapted to fit over the top of said upturned flange on the mower.

6. A detachable sharpener for a cross-flow mower having a carriage and a cylindrical reel mounted thereon for rotation about a horizontal axis extending laterally of the carriage, said reel having a plurality of circumferentially spaced blades with sharp outer leading edges, motor driving means for rotating said reel with the lower blades moving in the forward direction of travel of the mower, a blower conduit cooperating with said reel to form a blower of the cross-flow type with air flowing through the reel from inlet to outlet regions thereof, said blower conduit including upper and lower wall sections and side wall sections extending rearwardly of said reel, at least a portion of said inlet region opening in said forward direction of travel with the bottom and lower front portion of the reel uncovered and exposed to material to be mowed, the crossflow blower action and the blades of the reel mowing material without the aid of a fixed blade in shearing relationship with the reel blades, and a hinged plate mounted on said carriage behind the lower portion of said reel and rotatable about an axis extending parallel to the reel axis, said detachable sharpener comprising a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of said reel, a rear section joined with said front section, and means for attaching said rear section to said hinged plate of the mower with said front section extending beneath the mower reel with respect to the normal upright position of the mower, whereby downward movement of said hinged plate of the mower and rear section of the sharpener will bring said front section into sharpening engagement with the reel and the blades thereof sharpened with the mower in its normal upright position and the reel driven by said motor driving means. 

1. A detachable sharpener for a cross-flow mower having a carriage and a cylindrical reel mounted thereon for rotation about a horizontal axis extending laterally of the carriage, said reel having a plurality of circumferentially spaced blades with sharp outer leading edges, motor driving means for rotating said reel with the lower blades moving in the forward direction of travel of the mower, and a blower conduit cooperating with said reel to form a blower of the cross-flow type with air flowing through the reel from inlet to outlet regions thereof, said blower conduit including upper and lower wall sections and side wall sections extending rearwardly of said reel, at least a portion of said inlet region opening in said forward direction of travel with the bottom and lower front portion of the reel uncovered and exposed to material to be mowed, the cross-flow blower action and the blades of the reel mowing material without the aid of a fixed blade in shearing relationship with the reel blades, said detachable sharpener comprising a treadle having a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of said reel, and attachment means for hingeably attaching said treadle to said mower rearwardly of the mower reel and intermediate the front and rear ends of the treadle with said front section extending beneath the mower reel with respect to the normal upright position of the mower and the rear section accessible for foot operation, whereby pressure on said rear section will bring said front section into sharpening engagement with the reel and the blades thereof sharpened with the mower in its normal upright position and the reel driven by said motor driving means.
 2. A detachable sharpener in accordance with claim 1 in which the rear section has a width approximately equal to the width of said reel and is stiffly flexible, whereby pressure on different laterally spaced regions of the rear section produces laterally different engagement forces on said front section.
 3. A detachable sharpener in accordance with claim 2 in which said front and rear sections are sections of a unitary sheet of stiffly flexible material.
 4. A detachable sharpener in accordance with claim 3 in which the mower has a flange behind the lower portion of the reel, said attachment means including an upturned strip of stiffly flexible material fixedly attached to said unitary sheet, and means for removably attaching said upturned strip to said flange.
 5. A detachable sharpener in accordance with claim 3 in which the mower has an upturned flange behind the lower portion of the reel, said attachment means including an upstanding strip fixedly attached to said unitary sheet, and a downwardly extending section on the front side of said upstanding strip above said unitary sheet, said downwardly extending section and the adjacent portion of the upstanding strip being adapted to fit over the top of said upturned flange on the mower.
 6. A detachable sharpener for a cross-flow mower having a carriage and a cylindrical reel mounted thereon for rotation about a hOrizontal axis extending laterally of the carriage, said reel having a plurality of circumferentially spaced blades with sharp outer leading edges, motor driving means for rotating said reel with the lower blades moving in the forward direction of travel of the mower, a blower conduit cooperating with said reel to form a blower of the cross-flow type with air flowing through the reel from inlet to outlet regions thereof, said blower conduit including upper and lower wall sections and side wall sections extending rearwardly of said reel, at least a portion of said inlet region opening in said forward direction of travel with the bottom and lower front portion of the reel uncovered and exposed to material to be mowed, the cross-flow blower action and the blades of the reel mowing material without the aid of a fixed blade in shearing relationship with the reel blades, and a hinged plate mounted on said carriage behind the lower portion of said reel and rotatable about an axis extending parallel to the reel axis, said detachable sharpener comprising a front section of stiffly flexible material with an abrasive surface on the upper side thereof adapted to extend across the width of said reel, a rear section joined with said front section, and means for attaching said rear section to said hinged plate of the mower with said front section extending beneath the mower reel with respect to the normal upright position of the mower, whereby downward movement of said hinged plate of the mower and rear section of the sharpener will bring said front section into sharpening engagement with the reel and the blades thereof sharpened with the mower in its normal upright position and the reel driven by said motor driving means. 